What OS is the Dell laptop running? If it is able to see and copy the files on the CDs to its hard drive, you can use any number of ways of getting the info to your iMac - see this Apple article for methods.
If the PC cannot read the CDs (I presume you have already tried to read them in your iMac, is that right?) you may need to use a data recovery service such as DriveSavers. They do great work and have been known to recover data off of even badly damaged media, but they are not cheap.
Best of luck.
Thanks for your suggestions. The Dell is running W98 as its OS. It's an Inspiron 3500 laptop with an internal CD drive (interchangeable with a 3.5" floppy drive). The Dell is reading the disks perfectly well, but these are commercially-produced disks of Italian literature with indexing and search facilities, so they have complicated files. Of the Apple suggestions, the best seems the Apple translation service, but that is available only in the U.S. Of the others, I can't see how to connect the two computers, and even if I could, whether the data and the file formats could be translated into OSX. Is this a dead end?